I hate having to say “the controversial” in this case, but as usual, it’s controversial because Conservatives don’t want to pass anything making it any less acceptable to attack anyone who isn’t a straight white cis-gendered males in this world. Making it illegal to discriminate against a trans* person, in the same way as it’s illegal to discriminate against any other non-ciswhitestraightmales, well, would simply be a bridge too far to most of them. So they’ve been fighting it with the rhetoric that it would allow sexual predators to assault women in bathrooms by pretending to be transgender. They’ve honestly smeared it throughout the media and throughout the political discourse as “The Bathroom Bill”.